a) Field of the Invention
The invention is directed to a changing device for receiving optical elements, particularly for microscopes, for implementing incident illumination of specimens or objects and for observation thereof through appropriate shaping and guiding of the beam path by beam splitting and/or beam deflection.
b) Description of the Related Art
Reflector slides which are preferably arranged in the telecentric part of the microscope beam path are known for this purpose in microscopes. With regard to pixel-exact imaging of the object on the CCD matrix of a CCD camera, this reflector slide has drawbacks, including that the object or specimen can easily be put out of alignment with respect to the optical axis because of the end stops of the slide in the guide. In particular, for example, sequential recordings of objects or specimens with different wavelengths can then only be brought into coincidence by corresponding software, which requires increased resources.
In microscope applications requiring the greatest possible accessibility for manipulators and other tools for influencing or manipulating the object, the space above the object is often subject to especially restrictive requirements. It must be as free and accessible as possible so that work can be conducted without hindrance and the object can be manipulated. One such requirement, for example, provides for the use of up to five manipulators which extend in direction of the objective at 45° to the horizontal plane and which must be operated in a corresponding manner. These manipulators, which are applied from the front and sides, limit the available space for a required objective changing device, for example, and for possible illuminator components in such a way that, depending on the distance from the object, certain width dimensions and distances from the perpendicularly extending optical axis of the microscope may not be exceeded or must be adhered to.
DE 102 35 388.3 proposes an optical arrangement with a telecentric beam path, e.g., a microscope arrangement, which comprises an objective imaging at infinity, at least one eyepiece, and a tube lens which is arranged between the objective and the eyepiece at a fixed distance from the objective. A telecentric, i.e., parallel, beam path exists in the space between the objective and the tube lens. Arranged in this portion of the beam path are, for example, beamsplitters or other optical components which are arranged in a turret and can be introduced into the beam path.
EP 1 093 002 A2 discloses an apparatus for changing objectives in microscopes which ensures that, for example, the manipulators or objects or specimens which are to be observed or manipulated are protected against damage when changing objectives. This is achieved by providing an objective turret carrying objectives which is rotatable around an axis at an inclination with respect to the optical axis of the microscope beam path. The objective turret of the microscope is arranged so as to be laterally offset and this offset is defined with respect to one side wall of the microscope stand. Due to this offset of the turret and the resulting inclination and positioning of the axis of rotation of the turret, a substantially linear motion from the front wall to the rear wall of the microscope stand is generated in the region of the work position of the objectives when changing objectives.
This apparatus is directed only to a well-known objective turret in which other optical elements which influence the beam path cannot be arranged.
A quick-changing device for dichroic beamsplitters in fluorescence microscopes is described in U.S. Pat. No. 6,683,735 B2. A disk which is rotatable around an axis and comprises the individual beamsplitters and filters is provided in the microscope beam path. The disk is driven by a motor which is controlled by a computer. The required splitters and filters can be introduced into the beam path of the microscope by displacing the disk. However, this device has a drawback that should not be underestimated. The disk occupies a relatively large amount of space in the region of the beam path because the diameter of the disk must have relatively large dimensions in order to accommodate the splitters and filters.